Cold blast jet engine



March 27, 1956 5, E BQHRER 2,739,443

cow BLAST JET ENGINE Filed May 25, 1955 I United States Patent C) COLD BLAST JET ENGINE Samuel E. Bohrer, Long Beach, Calif. Application May 25, 1953, Serial No. 357,036

3 Claims. (Cl. 6035.6)

This invention relates to a jet type engine of the cold blast type which combines the performance characteristic of the screw type propeller with jet reaction.

An object of my invention is to provide a novel means whereby a portion of the blast of cold air is used to cool the engine driving the propeller and this air when warmed is, in turn, used to assist in the jet reaction.

Another object of my invention is to so arrange and proportion the various parts of the nacelle and the conduits that a maximum jet thrust is produced for the amount of power produced by the engine.

Other objects, advantages and features of my invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing:

Figure l is a perspective view of my jet engine.

Figure 2 is a longitudinal sectional view of the same.

Figure 3 is a diagrammatic longitudinal sectional view to illustrate the various proportions and arrangements of parts.

Referring more particularly to the drawing, the numeral 1 indicates an outer shell, the forward portion 2 of which is substantially cylindrical and the rear portion 3 of which is conical. An intake ring 4 extends'into the front of the shell 1 and particularly the portion 2 and is arranged axially of the shell 1, substantially as shown. I have found that it is desirable that the intake ring 4 shall be slightly conical, the angle of the walls, however, being not over 5 from a straight horizontal line. An engine 5 is positioned within the shell 1 and within a nacelle 6. This nacelle conforms in shape to the front portion 2 of the shell 1 and is spaced inwardly, therefrom to provide an air flow space 7. The engine 5 is preferably of the internal combustion type and this engine drives a centrifugal impeller 8 which is positioned in axial alignment with the intake ring 4-. The impeller moves the air radially and thence into the space 7, as shown by the arrows.

The radially moving air stream strikes the front surface 9 of the shell 1 to produce a forward thrust, as is usual and Well known in this art. After the air leaves the space 7 it moves into a conical path 10 to the jet outlet 11. The jet thrust is, of course, generated at the outlet 11 and the length of the outlet pipe may vary with the particular installation of the engine. For additional thrust I may extend the exhaust pipe 12 of the engine to the end of the nacelle 6 where the hot exhaust gases mingle with the hot air blast, thus materially increasing the jet effect.

In order to cool the engine 5, I provide a plurality of slots or openings 13 in the nacelle 6 and a part of the cold air stream is deflected upwardly, as shown by the arrows 14, and directed over the engine 5. A bafile plate 15 extending over the engine 5 causes the air stream to move towards the front of the engine and thence upwardly and rearwardly through a duct 16 where the cooling air thus passes into the rear conical portion of the nacelle 6. The air, having been warmed when passing over the engine 5, creates an additional thrust when it passes into the outlet pipe 11. Certain dimensions of my jet engine are critical in order that the maximum thrust may be obtained. 1 have shown these dimensions in Figure 3 and they are as follows: The diameter of the intake ring 4 is indicated as E, the diameter of the front part of the nacelle 6 is indicated as D, the diameter of the rear portion or outlet of the nacelle 6 is indicated as X, and the diameter of the outlet pipe 11 is indicated as J, the length of the forward or cylindrical portion of the nacelle 6 is indicated as L. With all of these dimensions measured in inches (or some common unit of measure) the proportions are as follows:

E X J .38 -.15 -.40 l.01 A variation of plus or minus 10% is allowable.

With the dimensions as shown, I secure the maximum thrust for the horsepower output of the engine 5.

Having described my invention, I claim:

1. A cold blast jet engine comprising an outer shell, the rear of said shell being conical in shape, said shell having an axially positioned air intake ring in the front thereof, an engine positioned within said shell, a nacelle surrounding said engine and positioned Within the shell, said nacelle being spacedfrom the wall of said shell to form an annular air passage, said shell having an air outlet at the rear thereof, an impeller connected to said engine and positioned back of and in axial alignment with said air intake, said nacelle having openings therein communicating with said air passage, said openings admitting air to the engine for cooling purposes, a bafile arranged above the engine, the cooling air passing around the baffle after traversing the engine and moving thence into said nacelle.

2. A cold blast jet engine comprising an outer shell, the rear of said shell being conical in shape, said shell having an axially positioned air intake ring in the front thereof, an engine positioned within said shell, a nacelle surrounding said engine and positioned within the shell, said nacelle being spaced from the wall of said shell to form an annular air passage, said shell having an air out let at the rear thereof, an impeller connected to said engine and positioned back of and in axial alignment with said air intake, said nacelle having a plurality of slots arranged therein rearwardly of said engine and open into said air passage, a baffle above said engine, said nacelle having an air duct opening into the rearward portion of the nacelle and arranged above the engine whereby cooling air is drawn around the engine, thence through said duct, and thence into the nacelle.

3. A cold blast jet engine comprising an outer shell, the rear of said shell being conical in shape, and a jet outlet at the rear of said shell, an axially positioned air intake ring in the front of said shell, an engine positioned within said shell, a nacelle surrounding the engine and arranged within the shell, said nacelle being spaced from the Wall of said shell to form a conical air passage, the rearward portion of said nacelle being conical to conform to the shape of the rear portion of said shell, and said nacelle having an outlet at the rear thereof, the proportion of the diameter of the intake ring to the diameter of the front portion of the nacelle being substantially .38, the diameter of the outlet of the nacelle to the diameter of the front portion of the nacelle being substantially .15, the diameter of the jet outlet of the shell to the diameter of the front portion of the nacelle being substantially .40, and the axial length of the front portion of the nacelle to the diameter of the front portion of the nacelle being substantially 1.01.

References Cited in the file of this patent UNITED STATES PATENTS 2,396,911 Anxionnaz et al Mar. 19, 1946 2,401,941 Lee June 11, 1946 2,635,420 Jonker Apr. 21, 1953 

